Inductance system



INVENTOR. v

3 SheetsfSheet 1 SGM/io,

L. A. GEBHARD INDUGTANCE SYSTEM Flled Dec 23 1929 Feb. 16,V 1932.

' Feb. 16, 1932.

L. Af GEBHARy v 1,845,406

INDUGTANCE SYSTEM 5 Sheets-Sheet 2 Filed Dec. 25, 1929 INVENTOR. (ycomenagw,

TTORNEY Feb. 16, 1932. L. A. GEBHARb 1,345,406

INDUCTANCE SYSTEM F'iled Dec. 23, -1929 '3 Sheets-,Sheet 3 INVEN TOR. A.

TTORNEY Parma-d Feb. 16, 1932 UNITED STATES PATENT OFFICE LOUISAQGEBHARD, OF WASHINGTON, DISTRICT OE COLUMBIA, ASSIGNOR TO WIRED RADIO,INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE INDUCTANCE SYSTEMApplication led December v23, 1929. Serial No. 416,158.

My invention relates broadly to high frequency inductance systems andmore particularly to a construction of coupling 1nductance for highfrequency signal transmission systems.

One of the objects of my invention is to provide a mechanical system foradjusting the effective number of turns of inductance in a signaltransmission circuit and controlling the coupling of the transmissioncircuit with respect to the radiation system.

Another object of my invention is to provide a construction ofinductance system which may be readily adjusted to predeterminedpositions for fixing the effective inductance in the transmissioncircuit and the coupling of the transmission circuit with respect to theradiation system.

A further object of my invention is to provide a construction ofadjustable inductance system by which a maximum value of inductance maybe connected in the transmitter circuit and the coupling varied withrespect to the radiation circuit by mechanical means variable withrespect to each other along the inductance in such manner that theeffective inductance may be varied throughout the entire length thereoffor tuning the transmitter circuit while a minor portion of theinductance may be effectively selected for connection in the radiationcircuit for varying the coupling between the transmission circuit andtheradiation circuit.

Still another object of my invention resides in the construction of avariable inductance system having means for predetermining the positionof a pair of variable contactors along a helical `inductance andselectively setting the contactors in desired positions for fixing thefrequency and coupling adjustment of a signal transmission system.

A stillfurther object of my invention is t0 provide -a'construction offluid cooled high frequency inductance system having means Lfor variablyincluding an effective number of turns of inductance in the transmittercircuit and a smaller number of turns in a coupling circuit for couplingto a radiation system while maintaining all of the turns of theinductance at a predetermined temperature by means of a Hind circulationsystem.

Other and further objects of my invention reside in the construction ofhigh frequency inductance system set forth more fully in thespecification hereinafter following by reference to the accompanyingdrawings, in which:

Figure l shows a lateral cross-sectional View taken through atransmitter panel and illustrating the arrangement of high frequencyinductance system of my invention with parts thereof shown partially incrosssection and partially in elevation; Fig. 2 shows a side elevationof the inductance system of my invention; Fig. 3 is a rear view of theinductance system looking in the direction of arrow A in Figure 1; Fig.4 is an enlarged cross-sectional view taken through one turn of theinductance adjacent one end thereof and showing the cooling fluidconnection thereto; Fig. 5 is a cross-sectional View taken through theend support of the rotatable adjusting means for controlling theeffective number of turns of the inductance in the transmitter circuitand the ycoupling of the transmitter circuit with respect to theradiation circuit; and Fig. 6'is a diagrammatic View showing the wiringarrangement of the transmitter circuit and radiation system embodyingthe principles of my invention.

. 'In high frequency transmission systems employing screen grid tubes,it is desirable to have the output circuit contain as much inductance aspossible at the particular frequency of operation. This 1s particularlydesirable for efcient operationat high frequencies and may beaccomplished by having the inductance coil in the electron tube systemat the transmitter arranged so that the effective inductance iscontinuously variable throughout the length thereof by means of a.slider which passes over all of the turns of the coil. It is alsodesirable t0 piovide another v adjustable slider on the inductance toeffect a continuously variable coupling or other adjustment. Thecoupling adjustment slider may be located at .a point along the induc-`tance which provides a lower effective induct-ance than is required bythe slider which is used for the tuning adjustment. This arrangementpermits a system to be employed in which the sliders do not pass eachother but where the sliders may be progressively changed in positionthroughout the length of the inductance. The inductance system of a highfrequency transmitter should be maintained at constant temperature forsecuring maximum eiiiciency in operation, and vthe frequency change andvariable coupling system of my invention is designed to permit change inthe effective inductance and effective coupling' between the transmittercircuit and radiation system while maintaining the inductance elementsat constant temperature.

Referring to the drawings in more detail, reference character 1designates the inductance coil which is in the form of a fiat tubularmember having the turns thereof located A substantially in verticalplanes and supported in helical formation by means of insulatedlaterally extending spacer members 2 which are supported at oppositeends by means ofend plates 3 and 4. Screws 5 pass through end plates 3and 4 securing the inductance in position with respect to the insulatedframe. The end plate 4 has a bearing plate 6 secured adjacent the centerthereof in which rotatable shaft 7 is journaled for rotary movement.'

The shaft 7 is in the form of a hollow conductive tube which enclosesthe screw 8 which is secured to the insulating member 9. The

u slider 10 is actuated by the rotation of shaft 7.under control ofcrank 14. The shaft 7 contains a longitudinally extending slot 7 athrough which screw 11 carried in slider 10 projects. The inner end ofscrew 11 engages the screw threads in the screw 8 which threads are cutto correspond to the pitch of the turns of the inductance coil 1. Therotation of shaft 7 causes turning of slider 10 which moves along thecoil 1 in accordance with the position of the turns. The slider 10carries l brush members 12 which engage opposite sides of the turns offlattened tubular inductance 1. In order to impart rotative movement toshaft 7, I provide the crank 14 operative from the front of the controlpanel 17, which crank is insulated from shaft 7 by means of insulatingmember 13. Rotative movement of the crank 14 imparts correspondingmovement to the beveled gears 15 operating a counter 16 which is visiblefrom the front of the control panel 17 of the transmitter therebypermitting resetting ofthe slider to any selected point along the coil.The counter 16 is mounted upon plate 17 awhich is supported byinsulating members 18 from the end plate 4. A second s1ider-19constituted by brushes engaging opposite sides of the turns of flattenedtubular inductance 1 is arranged to control the coupling between thetransmitter circuit and the associated radiating circuit. Slider 19 ismounted on rod 20 which slides longitudinally into tube 21. In order toprevent loss motion or displacement of the rod 20, the tube 21 is madesquare-in cross-section to receive theA rod 20 which is square incross-section. The tube 21 is secured to arm 22 which is connected withbeveled'gear 23 as shown more clearly in Fig. 5. A brace 24 extendsbetween one end of arm 22 and the extremity of the tube 21 therebyrigidly strengthening the movable assembly. The arm 22, brace 24 andgear 23 are secured together by means of pins 25 or the parts may besweated or otherwise connected for forming an assembly rotatable inunison. The assembled group of parts 22, 23 and 24 are arranged torevolve about shaft 26 which is rigidly secured in `support 27 by meansof pin 28. The support 27 is carried by the insulating members 41 and 42which are supported from the base 40 by a suitable bracket or othermeans. In order to impart movement to gear 23, arm 22 and brace 24, Iprovide/resilient washer members 29 and 30 which serve as spacer meanson each side of the assembled sets of parts 23. 22 and 24, permittingeasy turning of gear 23 under control of gear 31 actuated by rotativemovement of the beveled gears 35 through shaft 32 and insulatingconnecting. member 34 which interconnects the gear system 35 with thegear system 31-123. The insulating member 9 which is fixed to thethreaded rod 8 is connected by screw threaded portion 30a of shaft 26with the rigid shaft 26 so that central rod 8 is maintained stationarywhile the hollow tubular shaft 7 revolves over the screw threaded rod 8as an envelope.` In order to insure a tight connection between insulatedrod 9 and shaft 26, I apply a suitable locking cement for binding thescrew threads 30a of the insertable shaft 26 with respect to the socketportion of insulating member 9. The shaft 32 which interconnects beveledgears 35 and 31 is journaled at one end in bracket 33 and at the otherend in bracket 43. The beveled gear 35 is intermeshed with acorrespondingly positioned beveled gear which is operated by shaft 36and crank 37 from the front of the panel 17. `The beveled gears 38 whichare operated in accordance with the rotation of shaft 36 under controlof crank 37 connect with the counter 39 and enable readings to be takenfrom the front of panel 17 for predetermining the position o ff theslider 19 with respect to the inductance 1. The counter 39 ismountedupon the plate -17 a in a manner similar to counter 16. The end plate 3is apertured adjacent its center as shown in Fig. 3 to permit therevolving of the parts 21. 22 and 24 through 360 degrees or somemultiple thereof for moving the slider 19 over predetermined bushing 6aassociated therewith, and collar 45 with the hollow tubular shaft 7. Theconnection to the slider 12 is completed through the split brush 46which engages the surface of the hollow tubular shaft 7, through slider10, flexible spring 47, and to the parts of slider 12 which wipesopposite sides of each of the turns of the fiat tubular inductance 1.The connection to 'brush 19 is made through binding post 48, bearingblock 27, shaft 26. arm 22, tubular member 21, brush device 49, and rod20. The brush 49 maintains a frictional grip upon rod 2O as the rod isadjusted Witl respect to the tubular supporting member 21. The resilientwasher members 29 and 30 are of the disc shaped spring type havingradial slots to provide a good connection between the bearing support 27and the revolving group of parts 23, 22 and 24.

The inductance system is maintained in' permanent position and coolingfiuid supplied to the hollow tubular inductance as illustrated. Theinductance 1 has flattened side walls 50 providing a narrow fluid.circulating path indicated at 52. The iattened tube is wound edgewisewith respect to the laterally extending frame member 2. The coolingfluid enters one end of the coil, passes through the coil, anddischarges from the other end thereof. The fluid connection for theentrance and discharge of the fluid is shown more clearly in Fig. 4. Theexterior of the tubular inductance member is indicated at 51 and thehollow interior thereof shown at 52 with the end plugged as indicated at53 which prevents the cooling fluid from fiowing out of the end of thetube. Into the side or edge of the tubular conductor 51, l provide thetube 54 which is sweated therein to provide communication with theinterior fluid passage 52. Over the tube 54 there is placed aninsulating tubing 55 which serves to complete the path for the coolv ingfiuid to or from the inductance per se, and at the same time serves toinsulate the ends of the inductance from the remainder of the coolingfluid circuit. Clamps 56 are provided to hold the insulating tubing onto the tubing 54. this construction the inductance is 'formed of arelatively fiat tubular envelope closed at each end and into the sidesof the envelope adjacent each end thereof, there is admitted ordelivered therefrom a suitable cooling Huid.

Figure 6 diagrammatically illustratesthe connect-ion of the inductancesystem 'of my invention between the output circuit of a screen gridpower amplifier circuit and a radiation system. The last stageof poweramplification is shown'as including a screen grid tube 60 in theoutputcircuit of which the fluid cooled inductance system 1 is connected.The'slider 12 connects to the plate electrode of the electron tubesystem and one end of the inductance connects to the other end of theoutput system of electron tube 60.

Proper tuning capacity indicated at 57 may be introduced across aselected number of turns of inductance by means of switch 58. Theradiation system is shown as including an antenna 61 and ground 62 inseries with tuning inductance 63. The slider 19 connects throughcondenser 64 with the radiation circuit and by adjustment of slider 19along inductance 1 the coupling between the output system of electrontube and the radiation efficiency in high frequency signal transmission,and while I have described a certain preferred embodiment of myinvention, I desire that it be understood that modifications may be madeand that no limitations are intended other than those imposed by thescope of the appended claims.

What I claim as new and desire to secure by Letters Patent is asfollows:

l. A high frequency inductance system comprising an insulated framestructure, a fluid cooled inductance spirally positioned within saidinsulated frame structure, a central shaft extending through said framestructure, said shaft being divided into two conductive portionsinsulated from each other, a pair of brush contact membersconcentrically related to said central shaft and respectively supportedby portions of said shaft which are insulated from each other andindependent means for adjusting said brush contact members along saidinductance from opposite ends thereof toward the center.

2. In a high frequency inductance system, an insulated frame structure,an inductance spirally positioned within said insulated frame structure,a central shaft eXtendng through said framestructure, said shaft beingdivided into two conductive portions insulated one from the other,abrush engaging the turns of said inductance and operative under controlof Vvrotary movement of said central shaft, an independent brushengageable with the turns of said inductance, said brushes beingrespectively supported by portions* of said shaft which are insulatedfrom each other, and means for advancing said independent brush alongsaid inductance from the end thereof toward the center, said meansoperating independently of the rotary movement of said shaft.

3. In a high frequency inductance system,

an insulated frame structure, a spirally positioned fluid cooledinductance mounted within said frame structure, a` shaft memberextending through said frame structure, said shaft'member being dividedinto a pair of separate portions insulated one from the other, a contactdevice engaging the turns of said inductance and shiftable under controlof said shaft member, an independent contact device engageable with saidinductance, said contact devices being respectively rotatably supportedby portions of said shaft which are insulated. from each other, and

i separate controls for imparting independent movement to each of saidcontact devices.

4. In a high frequency inductance system comprising an insulated framestructure, a fluid cooled inductance spirally positioned within saidinsulated frame structure, a central shaft extending through saidinductance, means dividing said shaft into a pluralityof portionsinsulated one from the other, a brush contact device engaging the turnsof said inductance and shiftable in position with respect thereto undercontrol of one portion of said shaft, an independent brush contactdevice centered with respect to the other portion of said shaft, andmeans for driving said independent brush contact device around saidshaft for engaging the turns of said inductance independently of therotation of said shaft and independently of the movement of said firstmentioned brush contact device.

5. In a high frequency inductance system, an insulated frame structure,a fluid cooled inductance spirally mounted Within said insulated framestructure, a rotary shaft journaled centrally with respect to saidinsulated frame structure, said shaft being divided into two portionswith an insulating connector therebetween, a contact devicer engageablei with the turns of said inductance and adapted to be rotatedV aroundone portion of said shaft, a separate contact device engaging the turnsof said inductance and controllable by the rotative movement of theother portion of said shaft, and means for independently inductancespirally mounted within said frame structure, a shaft member extendingcentrally through said inductance, said shaft member including aninsulating connector Y dividing said shaft member into two independentportions, a brush Contact device engageable with the turns of saidinductance and shiftable along said in ductance in accordance with therotation of said shaft, an independent brush contact device arranged toengage the turns of said inductance, a carrier concentrically positionedwith respect to the other portion of said shaft and having sliday bleconnection with said independent brush contact device, and means, forimparting rotary movement to said carrier independently of the rotarymovement of said shaft for adjusting each of said Contact devices alongsaid inductance. l

7. A high frequency inductance system comprising an insulated framestructure, an inductance spirally positioned within said insulated framestructure, a rotary shaft extending through said inductance, said shaftbeing divided into a pair ofindependent p0rtions insulated one from theother, a contact device engaging the turns of said inductance andcontrollable in position along said inductance bythe rotatableadjustment of one portion of said shaft, a separate contact deviceengageable with the turns of said inductance, a rotatable carrierconcentrically positioned with respect to the other portion of saidshaft, slidable connecting means interposed between said carrier andsaid separate ncontact device, and means for imparting rotary movementto said carrier independently of the rotary movement imparted to saidshaft for effecting an adjustment of eachy of said contact devices alongsaid inductance.

8. vIn a high frequency inductance system, a helical tubular'inductancemember, a shaft disposed in the axis of said helical member,

said, shaft being divided into two portions insulated from each other, acontact member engaging the turns -of said inductance member, means formoving said contact member along said inductance member under control ofone portion of said shaft, an independent contact member engaging theturns of said inductance member, means for moving said independentcontact member along said in ductance member under the control of theother portion of said shaft, a fluid inlet member attached to said'tubular inductance member at one end thereof and communicating with theinterior-thereof, and a fluid outlet member attached to said tubularinductance member at the opposite end thereof and communicating Withtheinterior thereof, whereby cooling fluid is delivered to one end ofsaid tubular inductance member and flows' through the entire length ofsaid member to the opposite end thereof.

9. In a high frequency inductance system, a helical tubular inductancemember, a shaft disposed `in the axis of said helical member, saidshaftbeing divided into two portions insulated lfrom each other, a contactcontact member along said induct-ance member under the control of theother portion of said shaft, a fluid inlet member attached to saidtubular inductance member at one end thereof and communicating with theinterior thereof, and a iuid outlet member attached to said tubularinductance member at the opposite en d thereof and communicatin with theinterior thereof, whereby cooling uid is delivered to one end of saidtubular inductance member and flows through the entire len h of saidmember to the opposite end thereo 10. In a high frequency inductanceSystem, a helical tubular inductance member, a shaft disposed in theaxis of said helical member, said shaft being divided into two portionsinsulated from each other, a contact member engaging the turns of saidinductance member', means for moving said Contact member alongsubstantially the entire length of said inductance member under controlof one portion of said shaft, an independent contact member engaging theturnsA of said inductance member, means for moving said independentcontact member along said inductance member under the control of theother portion of said shaft, a fluid inlet member attached to saidtubular inductance member at one end thereof and communicating with theinterior thereof, and a fluid outlet member attached to said tubularinductance member at the opposite end thereof and communicating With theinterior thereof, Wherev by cooling fluid is delivered to one end ofsaid tubular inductance member and flows through the entire length ofsaid member to the opposite end thereof.

LOUIS A. GEBHARD.

